Receiver-shell.



J. B. EDWARDS.

RECEIVER SHELL;

APPLICATION FILED FEB. 10, 1912.

Patented Nov. s, 1914.

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RECEIVER-SHELL.

1,115,520., Speciication of Letters Patent.

.To all 'whom it may concern -Be it known that I, Josnria B. EDWARDS, `a citizen of the United States, residing at Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Receiver-Shells,` of .which the following is a specification.

My invention relates to receiver shells in general, and particularly to the type generally used for telephone service in which a tubular casing and ear cap are provided for inclosing the electro-magnetic apparatus, an

- object being to provide an improved method Vio of manufacturing the tubular casing portion of the type referred to.

It is very desirable that areceiver shell be light in weight and at the same time strong and durable to withstand the hard \usage it is subject to in being handled. Furthermore, it is essential that the'shell insulates the electro-magnetic apparatus carried thereby, therefore, various insulating compounds are used for this purpose, and on account of the high resistance and other advantageous features of rubber, compounds containin rubber are desirable, although usually agile. Also in .receivers of the type wherein the insulatingmaterial of the tubular shell portion lis threadedto receive an ear cap, such threaded portion is easily injured and the threads stripped. Therefore, 'I provide a thin metallic tubular support having a iared end turned back and threaded, the support being then covered with an insulating compound, but leaving the threaded portion exposed to receive the ear cap of the receiver, thus providing a receiver shell which is durable, cheap to manufacture, light in weight and overcomes the objections above pointed out.

For a more complete .understanding ofd my invention, reference is to be had to the accompanying drawing in which Figure l 'illustrates a metallic tubular shaped strengthening shell. cross-section along the line A-A of Fig. l, looking in thendirection of the arrow indicated thereon; Fig. 3 is a crosssection through the turned backthreaded portion of the nmetallic shell; and Fig. 4 illustrates the shell of Fig. l covered by an insulating coin-` pound.

'55 comprising two' semi-circular shaped halves Fig. 2 is a/ l12ga-nd 3, formed up of a thin sheet metal and having a number of 'perforations 4. The

larly shaped or formed to meet along the edges 5, 6, and secured together preferably by means of small clips 7 which are inserted intofthe openings 8 and then clenched as indicatdin the drawings. In order'to pro- Avide means for threading an ear cap to the handle or tubular portion l2 of the receiver shells, the iiared end of the halves 2, 3, is formed back'as indicated in Fig. 3, sothat it may be threaded to receive the ear cap. U In Fig. 4 I have shown the metallic casing l with the insulatinnsubstance 9 molded thereon, but leaving the threaded portion l0 exposed. In molding the insulating material 9 around the tubular shell l the said material 9 is simply allowed to project slightly beyond the inner surface of the tube l, as is indicated in Fig. 4, thus forming a homogeneous' structure, although insulating material may be molded on both the inside .and outside Tof the shell l.

Although I have indicated the tubular turned back portion 10, previous to molding the insulating material 9 thereon, this threading operation may also be performed after the material 9 has been molded onto the shell l so as-,to receive ear cap 11, as shown in-Fig. 4, and although I have illustrated and described a specific form of my mvention,I do not desire to be limited to the exact structure as illustrated and described, as itis apparent many changes and modifications thereof may be made, and I aim to cover all such changes and modifications as come within the spirit and scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is: ,e

1. A telephone receiver shell consisting of a thih strip or strips .of sheet metal containing perforations, suitable perforations arranged along the longitudinal edges of said strips of metal adapted to receive a' clamping or binding element, a pluralityv of small brads or strips fprojecting through said last mentioned per orations, the free ends of said strips being clenched to llock the adjoining edges of said strips 'ofmetal firmly into cylindrical form, and a coating of hard rubber or insulating compound disposed upon the exterior o Patented Nov. 3, 1914.

two halves 2 and 3 each are preferably simithe cylindrical shell thus formed, the first mentioned perforations in said metal assisting to secure said insulating compound securely in position thereon.

2. A telephone receiver shell consisting of a thin strip or strips of sheet metal con\ taining perforations, suitable perforations arranged along the longitudinal edges of said strips of metal adapted to receive a clamping or binding element, a plurality of small brads or strips projecting through said last mentioned perforations, the free ends of i said strips being clenched to lock the adjoining edges of said strips of metal firmly into cylindrical form, and a coating of hard rubber or insulating compound disposed upon the exterior of the cylindrical shell thus formed, the flared end ofsaid receiver shell being turned back and threaded to receive a suitable ear cap, said turned back portion being disposed Withreference to the body of the shell so as to leave a small antion and the exterior Wall of the shell, the

`f iI"stmentioned perforations in said metal Witnesses. f

' JOSEPH B. EDWARDS. Witnesses:

GEORGE E. MUELLER, CARRIE E. `ANDERSON.

Vnular cavity betweensaid turned back por- 

